Understanding of the Furfural Electrochemical Hydrogenation and Hydrogenolysis System in a Semi-Batch Reactor

Abstract

Furfural (FF) is a platform molecule that can undergo electrochemical hydrogenation and hydrogenolysis (ECH) over copper catalysts to form furfuryl alcohol (FA) and 2-methylfuran (FA) respectively. FA is a fine chemical used in creating furanic molds, and MF has been identified as a fuel candidate. An acidic electrolyte is necessary to obtain the MF product, however the acidic conditions are also the cause of homogeneous side reactions [1,2]. In our group we studied the kinetics of the FF ECH reactions in a 2-compartment H-cell connected to a solvent trap with inert gas sparging into the catholyte to promote the evaporation of MF to the solvent trap for capture. We showed the kinetics of the FF ECH reactions in 0.1 and 0.5M H2SO4 with concentrations of FF between 10 and 120 mM at -560mV vs RHE followed a non-competitive Langmuir-Hinshelwood model [3], in timeframes where side reactions did not influence the results significantly.In this work, we build on our previous kinetic study by modeling the system of competing reactions and MF transfer to the solvent trap. We show the importance of sparging inert gas into the catholyte to promote evaporation of MF for collection in the solvent trap to avoid side reactions of MF in the acidic catholyte.[1] Jung, Sungyup, and Elizabeth J. Biddinger. "Electrocatalytic hydrogenation and hydrogenolysis of furfural and the impact of homogeneous side reactions of furanic compounds in acidic electrolytes." ACS Sustainable Chemistry & Engineering 4, no. 12 (2016): 6500-6508[2] Jung, Sungyup, and Elizabeth J. Biddinger. "Controlling competitive side reactions in the electrochemical upgrading of furfural to biofuel." Energy Technology 6, no. 7 (2018): 1370-1379[3] May, Andrew S., Steven M. Watt, and Elizabeth J. Biddinger. "Kinetics of furfural electrochemical hydrogenation and hydrogenolysis in acidic media on copper." Reaction Chemistry & Engineering 6, no. 11 (2021): 2075-2086